html{
    font-size: 50px;
}
@num: 15;
@media screen and (min-width:320px) {
    html{
        font-size: 320px / @num;
    }
}
@media screen and (min-width:360px) {
    html{
        font-size: 360px / @num;
    }
}
@media screen and (min-width:375px) {
    html{
        font-size: 375px / @num;
    }
}
@media screen and (min-width:560px) {
    html{
        font-size: 560px / @num;
    }
}
@media screen and (min-width:720px) {
    html{
        font-size: 720px / @num;
    }
}
@media screen and (min-width:750px) {
    html{
        font-size: 750px / @num;
    }
}